linux-kernel - [PATCH v3 04/12] KVM: x86/mmu: Avoid pointer arithmetic when iterating over SPTEs

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Message-ID: <20230729004722.1056172-5-seanjc@google.com>
Date:   Fri, 28 Jul 2023 17:47:14 -0700
From:   Sean Christopherson <seanjc@...gle.com>
To:     Sean Christopherson <seanjc@...gle.com>,
        Paolo Bonzini <pbonzini@...hat.com>
Cc:     kvm@...r.kernel.org, linux-kernel@...r.kernel.org,
        Mingwei Zhang <mizhang@...gle.com>,
        David Matlack <dmatlack@...gle.com>,
        Jim Mattson <jmattson@...gle.com>
Subject: [PATCH v3 04/12] KVM: x86/mmu: Avoid pointer arithmetic when
 iterating over SPTEs

Replace the pointer arithmetic used to iterate over SPTEs in
is_empty_shadow_page() with more standard interger-based iteration.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
 arch/x86/kvm/mmu/mmu.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index b16092d71d3f..08d08f34e6a3 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -1696,15 +1696,15 @@ bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
 #ifdef MMU_DEBUG
 static int is_empty_shadow_page(u64 *spt)
 {
-	u64 *pos;
-	u64 *end;
+	int i;
 
-	for (pos = spt, end = pos + SPTE_ENT_PER_PAGE; pos != end; pos++)
-		if (is_shadow_present_pte(*pos)) {
+	for (i = 0; i < SPTE_ENT_PER_PAGE; i++) {
+		if (is_shadow_present_pte(spt[i])) {
 			printk(KERN_ERR "%s: %p %llx\n", __func__,
-			       pos, *pos);
+			       &spt[i], spt[i]);
 			return 0;
 		}
+	}
 	return 1;
 }
 #endif
-- 
2.41.0.487.g6d72f3e995-goog